Process for preserving materials of the powdery or mealy type



, wards external harmful influences.

Patented Aug. 31, 1943 r UNITED sT-Arss PATENT 1 ".rnsrownmY oRM LY Y-PE EgonHerberttS chwarz, Zurich, Switzerland h o-nrawmanfibnation s ptenib r za-ittcgse- Harms- 358,757, 11; Switzcrland; 'OctobeFS,' K

*It'is a generallyknownfactythatall-natural ences, such asmouldinesamustiness, dustiness,

moth or worm attack, infection, etc.

Until now, different processes have been proposed and employed, for avoiding these harmful influences whichver often cause completedestruction of the goodsj for instance, the storage of the materials in' air-tight and"closed receptacles, the addition "of chemical substances, or their constituents, I the pressing into compact form, etc. The well-knowngpressing process has provided the most successful, as a protection to- However, by means of the well-known stamping in and pressiiig'process, whereby "materials or'hiiiituresf in powder-form should keep'for aj'cons id-erable time without altering their original'physical; chemical and biological propertieai." e. in-a maiine corresponding to th-originalinteritioxi offthesematerials, the desired result could not be obtained, and this for at least one reasonnamely, that the materials to be, preserved,ywere not subjected to the appropriate pretreatment, for example,

sterilization, for destroying any possible bacillus,

microbes, spores, etc.

Suchmateri'alswhich were pressed-or stamped in withoutany pretreatment, showedwithinthe shortest time very serious changes, with regard to their physical properties, and their chemical compositionowing to the presence of microorganisms, causing decomposition or other alterations, The-desired result therefore, i. "e., the prescarv'ing of these materials towards internal and external influences for a longer period, could "notbe completelyobtained.

The purpose of the present invention, is to subject natural or artificial materials infpowder form,: destined "f or long storage, resp. for preservation, to such pretreatment 1 beroremenase pressing is resorted 3 to, and withoutthe addition of 'any foreign"matter,- for example chemicals or worlc and a essentialist;pressing= -(:l)"Thefsterilizatlon'o the s s, g ese,

count "orf the trosqmsnseiy hig'h I i'ciaini, (Cl. 99 rrej jw ile am yh tar materials under suchfjcdnditions, that after presscal and "physical proper ies; without any 9 '"e -in-; qualit 1 whatsoever; mid with the advantage,

that they can be kept for fanimlimited time and can'be used at any desired'pefiodj 'f'ur her more, presenting solidity, and volume reduction, facilitating s1:' d1"' iigeinainec'l'iahical' sense. v

{ The invention calls forasnw' r-preparatory I 1 e., -:d'e-

acilli, nncrobes, I larvae,- etc.):, don'taindin theiifater'ials "byf nature," or {ntefihg afterwards,

, h *s tifiictio-n 'of microorganisms aterials 'meahs ofwiolet ray atd thelike. I I, i (2) The suppression of the elasticproperties'bf the i materials, ty'means; 0f heat influence (3) i The elimination cr-ausmrcm-tiie"materials, by means of -cooling" and Lprepressing.

' As' mentioned above, the k oiv'n"'1neth'odfor preventing materials in powder-term; andthir mixtures, 'fr'Om' be'cbrnirig*s'lfitiilt, ot from chan ing their chemical composition, consistsinstarhping or pressing. The press processes known,

however, possessed several tunclam'efital di sadvantage on of ine disadvaiita'ges ot the knownprocessesconsistd therinpthat the ma- 'terials to be pressed star-contained" microbes,

bacilli and spores which were not liminatedfibut a s.;We .,.eddd, P9. t materia s respthes e materials were subjected to water steam, and'such like, to-prevent seeming m tajliing place. 1 Another'dfsadvantage of the"liibvvxiprocesses was to be time in the fact, the-t the most 'impsrtsm matter was overlooked, aeaeiyp sst "the materials-in powdeffbrmfl of different tinposition, could a only be subjected to definite pressures of thepress, in accordance vvith their physical and chemical p pperties, I Another point an a factor'ofthni ost ii icidiri 'im rt" been taken into 'accofint, 'i.*e. ,"ftiiat lira A powder form, cant-Oct ssefd withwheffls'ual piston, fitting closely o the-pfestiri inpmdit d rubbing. along the wa llfs'fbi amcilb n themiateri-al to he fiesseg afinbt e'scapej tliis quantity {or air tecsmes heated, e'reetiri etibonized appearances in the powdery material, thereby subjecting the physical, chemical and biological properties of the pressed goods to an alteration. As a result of this, the pressed material could not be used for its original purpose. The exposure of the materials to the influence of water or water steam, had the harmful eifect, that the water or steam remainingin the material created moulding tendencies. The addition of chemicals was accompanied by the disadvantags, that the pressed materials had to be puri- I noted from the instructions given for pretreatment, no foreign matter, for example, preserving or agglutinant means are added to the material to be preserved, resp. pressed.

After the pretreatment mentioned has been carried out, the materials are ready for pressing, and the process, according to the invention, consists therein, that a piston press, or such like is used for briquetting, i. e., shaping into bricks, whereby the piston diameter in comparison to the stroke, and to the diameter of the cylinder, or other cross-section bodies of the pressing chamber, are in a certain relation to each other, and furthermore, air-slits are to be provided in the piston, according to the materials to be pressed, permitting any air, gases, etc., becoming liberated from the material by pressing, to escape, in this manner a complete briquetting is the result.

The following dimensions have proved especially suitable:

Supposing, that the interior diameter of a pressing mould is 1 ,cm., the height of the inner pressing chamber of the pressing mould. ought to be 77. cm., therefore,

h=2.4 d (measured in centimeters) The dimensions of the piston are as follows:

The diameter of the piston (d1) must be (0.4 mm. smaller than the interior diameter of the pressing chamber (d), in the event of the latter having at the most cm. In this case the following equation would come into question:

d1=d0.04 (measured in centimeters) If at measures atthe most 50 cm., (11 must be 0.5 mm. smaller than d, and if d has at the most '75 cm. d1 must be 0.6 mm. smaller than d.

The dimensions of the air channels provided on both sides of the pistons are as follows:

If d is cm. at the most, the cross-section of these channels is to amount to 2 1 mm.

If (2 is 50 cm. at the most, the cross-section of these channels is 3 X 1.5 mm.

The diameter of the piston must therefore be smaller according to the above mentioned dimension, than the width of the pressing mould, so that any friction along the walls of the pressing mould is avoided in this manner, and any heat from friction which until now caused cases of carbonization in the pressed material does not arise.

The pressed goods retain therefore their original colour, composition and biological properties.

For the purpose of avoiding any material becoming attached to the piston, the lower surface of the piston can be carried out in a concave manner. The dimensions of this concave construction are:

0 mm. at the rim of the piston, 2 mm. at the vertical centre line of the piston, providing that the diameter of the piston is 25 cm. and 3 mm. at the most, and providing that the piston diameter amounts to 50 cm. at the most.

After the material has been emptied into the pressing mould, a thin piece of paper or such like can be placed by hand, or by means of an appropriate device on the material before the pressing piston is put into action, this, in order to avoid any material becoming attached to the piston. The thin piece of paper can easily be removed afterwards from the completed shaped piece.

The amount of mechanical pressure to be used, depends upon the dimensions of the pressing mould, i. e., upon the diameter and height of same, upon the properties of the material to be pressed, and upon the height of the material filled into the pressing cylinder for pressing. The pressures to be used for the diiferent cases, relating to different important foods, are given in kg./cm. as follows:

(a) For such kinds of meals as bran, cement flour, and generally, all dry powdery materials, with no oil or grease contents, the amount of mechanical pressure to be used is (p) P=3 d if sh=1 d p=4 d if sh=1.5 d p=5 d if sh=2 d (b) For smooth kinds of meals, such as rye, barley, indian corn, and generally, Where all powdery and mealy materials, containing very little oil or grease, are concerned, the amount of mechanical pressure to be used, is (p) i dif sh=1 d p=3 d if sh=1.5 d p=4 d if sh=2 d (c) For mixtures of mealy kinds of materials with butter oil, or grease, for artificial manure, milk powder preparations, and generally, for all mixtures containing a larger quantity of grease, the following mechanical pressure (p) is to be used:

Whereby the meaning of:

p=the mechanical pressure to be used, in kg./cm.

d=the diameter of the pressing chamber, in cm.,

and i sh=the height of the pressing cylinder for pressing the material filled in, in cm.

If any material treated in powder form according to the methods of the invention for the preparatory stage, is afterwards pressed in the appropriate press moulds in accordanc with the above formulas, a shaped piece Will be the result which has kept in every way its original properties, with the advantage, that it can be kept any length of time, and no exterior influences (smells, heat, cold, gases, etc.) can affect it- No harmful microorganisms (bacilli, eggs, spores, etc.) will have a chance to develop in such a product,

The material is fire-resisting, its outer surface-in the event 01 the shaped piece being An exceptionally important advantage of the invention consists therein, that the pressed material loses 2 -55% of its volume, due to pressing and interior air expulsion, depending upon the chemical composition and physical condition of said material, and regarded from the point of view of storage, delivery and treatment, this means a great progress. Finally, the pressed shapes, can be stored anywhere desired, without any further treatment or airing, even underground sites would have no effect on same, which turns out to be a great economy, in comparison to storage and treatment of unpressed goods.

The best method for protecting the shaped piece from becoming dusty, dirty or being affected by other influences, consists in wrapping same into Cellophane paper, by sticking down the edges. On the other hand, a special dipping lacquer, on the basis of acetylcellulose can be used to great advantage.

The finished shapes (preserves) can then be used by taking off the wrapping, and the product crushed by hand, or b some mechanical device. Thereafter the crushed material is absolutely equal to the fresh product. i I

To conclude, it is to be pointed out, that transgression of the present instructions as regards dimensions of the pressing mold, and of thepiston, either in the negative or the positive sense, or the increase or decrease of the mechanical pressure mentioned, would cause a disadvantageous change in the physical and biological properties of the powdery material, making any preserving out of the question and its original purpose would not have been served at all.

I claim:

Method of preserving materials or the powdery or mealy type which comprises the steps of sterilizing the materials, suddenly lowering the temperature of the materials, applying a preliminary pressure to said materials and forming a preliminary body, thereafter subjecting the preliminary body to final pressure to produce the final shaped product, allowing air to escape from within said preliminary body during the final pressing action," fresh air being also admitted to the outside of said preliminary body to cool it during the final pressing action. I

EGON HERBERT SCHWARZ. 

